When the sun sets
by LaurielS
Summary: It was supposed to be a humanitarian mission, providing medical and research aid to a planet. However, behind the peaceful front, not everything is as it seems, and the friendship between Spock and McCoy are put to the test. Friendship only. Sets after ST: Beyond, during one of the next five year missions.
1. Chapter 1

**When the sun sets**

Author's note: This story was inspired by the TOS episode, "All our Yesterdays", but should bear minimal resemblance to it. I hope you enjoy the Easter eggs I managed to slip in there!

Disclaimer: Not mine.

 **When the sun sets**

Star date 2270.8

The mission had started simply enough: the Federation had received news that the planet Vildle, which had just recently joined the federation after its leaders promised to lay down its arms and rule its citizens peacefully, may have a pandemic on the planet after reports of high death numbers. After much pressure, their leader, La'thar, had admitted to an infectious disease plaguing the planet and the Federation had immediately requested for medical and research aid on the planet. As the Enterprise was within the quadrant, their 5- year exploratory mission was halted and they were redirected to that faraway planet inhabited by humanoid Vildleans.

It later turned out that the situation was worse than they had expected—the death toll was up to tens of thousands and the virus had wiped out almost half of the population. Quickly, McCoy ordered for samples of the virus to be beamed up and treated as a BSL4 agent. After initial screens using cell lines and preliminary tests using organoids, it was finally determined that all species aboard were naturally immuned to the virus, and it was only then that Jim authorised a mission and allowed the medical and research teams, led by McCoy and Spock respectively, to beam down to the surface.

Three days later, all contact with the two teams ceased abruptly.

* * *

"Of all people, Spock, the last person I would expect to go on a mission with is you."

"As a matter of fact, doctor, the landing team usually consists of at least two ranked individuals, thus the possibility of both of us being sent to a mission is higher than yourself and a randomly selected ensign."

"Spock, you know that's not what I mean," sighed McCoy. Damn Vulcans and their probability.

Spock raised an eyebrow in response, "Then what do you mean, doctor?"

"Gentlemen, Gen-tle-men," chided Jim lightly as he saw McCoy prepare himself for a full blown rant, "please try not to fight too much down there."

McCoy rolled his eyes as the transporter beam disappeared around them.

* * *

McCoy was not having a good day.

The first thing that ticked him off was the medical facilities on Vildle. The largest hospital looked more like something out from a 1900s hospital, with a negligible isolation ward and patients grouped together without any real order at all. That had McCoy ranting about the spread of infectious diseases as the entire medical team attempted to reorder their system and make things more orderly.

The second and main thing were the patients.

The so-called afflicted patients were coughing and complaining of pain, but try as they might, they could not detect a problem. The medical team had compared each of the test results and scans with healthy patients, and apart from the usual variations between individuals, nothing seemed wrong.

And they were not allowed access to those who had succumbed to the disease.

"I need to see the physiological pathologies post mortem, dammit! These patients, as you call them, seem healthy, and I need to know what to look out for so that I can prevent any sudden demise!"

La'thar shook his head adamantly. "Doctor, the dead are sacred on our planet—surely you must know that. We cannot authorise any actions which may disturb them. You can only work with the patients we have here. I am sorry."

McCoy narrowed his eyes and was about to speak as Spock stepped forward gently. "We understand, La'thar. We will not pursue this further."

La'thar smiled and bowed, taking his leave. Spock ushered McCoy into a room.

"Spock, just what do you think—"

"I have been doing some research, doctor. The first victim was K'mez, the leader of the opposition faction. This was quickly followed by his family members and loyal supporters. Do you not think it is coincidental, doctor, that the first few victims of this disease are those of the opposition faction?"

"Are you implyin' that they are using the virus as a bioweapon?"

"Possibly. Another possibility could be that there was no virus at all, and the virus was simply an excuse to get rid of those who were opposing La'thar."

McCoy's eyes widened. "We need to find these people quickly, if we are to prevent any more deaths."

* * *

The whole team spent the next two days mingling with the natives whilst secretly gathering information about the circumstances surrounding the patients' deaths. From these natives, they soon got to know where the dead were laid to rest and the rotation timings of soldiers involved in the entire operation.

By the night of the third day, a plan was devised amongst the landing party. After knocking out a couple of guards, they managed to sneak into the cordoned-off area. Quickly, the medical team checked on each individual as the sciences surrounded them, guarding the small group. Two ensigns volunteered to be lookouts and placed themselves in strategic positions further away.

The instant McCoy laid his eyes on one individual, he knew something was amiss. After a quick inspection however, his fears were realised and McCoy felt himself go cold.

"Spock…" he whispered, as his eyes met Spock's, "these people did not die due to an infection."

"They were drowned."

 _Drowned._

 _Like the fates of those who had opposed La'thar before Vildle joined the Federation._

"Well, well who do we have here?"

"La'thar!" gasped a Science ensign as he took a step backwards.

The leader looked at them, a malicious glint in his eyes. Gone was the welcoming, good-natured and charismatic leader; in his place stood a cunning and ruthless ruler.

"I see you have discovered our little secret…" he sighed, then stepped away to reveal the armed soldiers he had brought with him, "I told you not to meddle in our affairs…"

Just as Spock was about to act, two soldiers stepped forward, pointing a gun at each one of their two lookouts. La'thar smiled as he saw Spock stall.

"See you later," came La'thar's voice.

The last thing they saw was smoke bombs being thrown at them.

* * *

When Spock awoke, he was immediately aware of the damp and significantly colder surroundings. As his eyes adjusted to the change in light intensity, he noticed an unconscious figure in a corner.

"Doctor!"

His call seemed to have the effect of waking the physician—and in fact, other humans as well, as Spock now realised, for Ensign Reeves in the neighbouring cell was now slowly regaining consciousness whilst Nurse Evans in the opposite cell let out a small groan.

The trained eyes landed on the Vulcan and the physician was next to him in a second. "Spock, y'alright?"

"I am well, doctor. I was merely ascertaining the status of our crew members."

McCoy resisted the urge to roll his eyes. _Would it really kill him to admit he was worried?_ "Well, now that you have ascertained the status, would you mind maybe THINKING OF AN ESCAPE PLAN?"

"Unfortunately, doctor, they have taken all our weapons and communication devices. However, I believe the Captain will be looking for us soon."

"Confident, Spock? Confident to just sit here and wait?"

"Indeed. I am scheduled to call Nyota today, and us being here will make that impossible. She will surely find it suspicious."

"But how is Jim gonna find us?"

McCoy did not miss the sudden subtle change in Spock's expression.

"I am sure he will."

* * *

"Captain, I believe I may have a plan in determining their coordinates."

"Yes, Uhura?"

"I got the Vokaya stone for Spock when we got back together," at this, Jim smirked, "and as you know, the Vokaya emits a certain signal—"

"—which I remember the formula to! Keptin! We can find them!"

"Then what are we waiting for, Chekov?"

"Aye Keptin!"

* * *

Sounds of footsteps made Spock and McCoy turn to look towards the entrance. A familiar figure came into view, and McCoy's eyes narrowed.

"Ah, you are all awake. Excellent," said La'thar slowly.

"Spit it, killer. What do you want," retorted McCoy, voice dripping with anger.

"Oh, very good very good," drawled La'thar, as he stopped in front of their cell, "all of you know too much. You must know you cannot leave here alive."

"If you kill us, you will be declaring war on the Federation!" shouted McCoy.

"Oh, don't you worry, doctor, you're not going to die by our hands," said La'thar, examining an old fashioned gun he pulled out of his bag, "Not directly, anyway."

With that, La'thar laughed and threw the gun into the cell before walking away. At the wave of his hand, the sprinklers above the cell started emitting a strange, coloured gas as glass walls came down around them. The gas didn't smell particularly like anything and it certainly wasn't suffocating them, but just as McCoy was about to quip about how useless the gas was, he saw something changing in Spock's eyes.

"Spock, y'hear me?"

There was no reply.

"Spock! Look at me! It's me, McCoy!"

But standing before McCoy, slightly bending with raging eyes, was no longer the Spock McCoy knew.

* * *

"Keptin, the signal is coming from underground, at the basement of the city's largest prison!"

"Alright. Sulu, assemble a team of 4 people from security. And bring your sword, you're coming with me."

"Yes, Captain."

"Chekov, tell Scotty to man the ship whilst I am gone. If I am not back in one hour, call the Federation."

"Aye, Keptin."

"Captain, I am coming with you," said Uhura, resolutely.

"Uhura, no."

"Captain," her voice was dangerously low.

"I'm sorry, Lieutenant, but that's final," said Jim, and he continued when Uhura attempted to interrupt, "I am not depriving you of this because you can't fight; I need you on the ship. We are near the neutral zone, and I need you to discern if Romulans are nearby, and your linguistics skills will be invaluable if any alien ships were to contact us. You need to be here."

Uhura looked at Jim.

"Alright, Captain. But you must inform me if anything happens."

Jim nodded and rushed off to the transporter.

* * *

"Spock, whatever you see is not real!" shouted McCoy desperately as Spock rounded upon him.

But it was no use.

"Nero," he heard Spock seeth between his teeth as he launched himself towards McCoy. McCoy tried to dodge, but Spock was too quick for him and before he knew it, Spock's fist collided with his stomach. He groaned and sank to the floor, narrowly dodging another fist aiming for his face. Seeing a way out, McCoy took the opportunity to run to the opposite side of the cell, but the Vulcan was faster. A couple of blows were aimed at his head and hurriedly blocked by McCoy, but as McCoy attempted to escape from the corner, Spock struck McCoy's chest, and the telltale crack of the bone echoed in his ears. McCoy collapsed in a fit of coughs as he fought down the blood that was rising in his throat.

"S-pock... Wake… up…" he struggled, as the Vulcan held him by his neck against the wall, suffocating him.

"You destroyed Vulcan. You will pay for it." Spock said in a low, menacing voice, his grip tightening.

"Is this… what you want, Spock? Are you… trying to kill me?" McCoy whispered, choking.

McCoy saw something shift in Spock's eyes and he took advantage of the sudden confusion to say more.

"Spock, do you remember who I am?"

 _That voice…_

"That's it, Spock! Try an' remember! The trips, the five year mission, Krall…"

Spock's hand wavered some more.

"Spock!"

McCoy knew that voice immediately.

 _Jim._

 _Jim is here._

That shout lifted McCoy's heart, but his happiness was shortlived as he turned to look at Spock.

The confusion was gone.

The raging eyes were back.

Spock swooped down and took the gun, cocked it against McCoy's abdomen, and pulled the trigger.

Point blank.

"NO!"

In an instant, that desperate cry penetrated Spock's mind. It was a cry he never wished to hear again after McCoy had collapsed in the small ship saving Jim from Krall*.

 _Jim._

In a flash, his mental state was back and he finally saw clearly the person in front of him.

 _McCoy._

The man was smiling weakly at him, his features twisted with pain.

"S-pock."

"Leonard."

Suddenly, memories of what happened and what he did came back to him like a bullet and he stared down at his hands, now red with McCoy's blood.

 _How could he..._

He felt sick.

"No…"

"Spock," gasped McCoy, his hands holding Spock's, "it's not your fault. The gas… it's hallucinogenic for Vulcans…"

 _No…_

The world seemed to change around him. He heard Jim bring La'thar down before Sulu took over the fight, easily dominating La'thar even without his sword. He heard Hendorff and the security team take down any leftover La'thar's supporters attempting to stop Kirk. He heard the doors unlock behind him as the glass wall lifted. He saw Jim look at him cautiously and then run over to support McCoy, before everything slammed right back into him as Leonard tugged his hand, coughing.

"Jim, Spock," he rasped, as he put both of their hands together and clasped both in his own, "not… your… fault…"

And then the world seemed to collapse a second time as Leonard's grip slackened, and Spock was heartlessly yanked back to the moment when old Vulcan was swallowed and his mother let go, disappearing forever.

 _No…_

* * *

*Alludes to my other story, Triumvirate

 **-To be continued-**

 **Reviews and comments are very much appreciated!**


	2. Chapter 2

**When the sun sets**

Author's note: Finally finally finally, I have completed chapter 2! Sorry for the long wait-my life has been really hectic, and I was at some sort of a crossroad where I had to make a life changing decision. But now that that's done, I'm back!

Disclaimer: Don't own anything.

 **Chapter 2**

In Jim's mind, coming back to the Enterprise was always a relief—it signified the end of a mission, where he will be safe and can finally relax.

He had never been so wrong.

Down in the cell, everything had been dark, and he hadn't been able to see anything very clearly; he hadn't been able to see the wounds on his friend, and he could certainly pretend not to notice the blood on the floor. However, once they materialised on the transporter, the brightness of the room illuminated Bones' condition clearly.

There was blood everywhere.

"Blood pressure dropping."

He barely registered as a flurry of doctors and nurses descend upon them, trying to stop the blood that was gushing out of Leonard's body. He barely noticed as the nurses laid McCoy flat on the floor and detailed all the wounds they could see to the doctors. He didn't even realise two of the nurses coming over to check on him and Spock-all he saw was the pale features of his best friend and the barely rising and falling movement of his chest. He saw the blood surrounding him, and felt the various bruises and broken bones of Bones' chest.

An oxygen mask was quickly fitted over McCoy's face.

"Prep blood units, this is an emergency."

Red, red, red… everywhere was red… even Jim's bright Gold uniform was no longer gold as the sickening crimson liquid spread all over.

"Condition stabilised. One, two three!"

He saw them lift Leonard onto a makeshift bed as the heart monitor began screaming.

"He's flatlining. Performing CPR now. One, two, three…"

And then, silence.

Shocked silence, as Jim saw his best friend being wheeled away, and his other best friend staring at his hands, uncomprehending.

"Spock," said Jim softly as he approached Spock.

"I shot him," repeated Spock.

"Spock, look at me," insisted Jim, "You were influenced by their drug. It is not your fault."

"I held the gun. I am therefore legally…"

"Spock, stop. Look at me."

Spock obliged.

"We will get through this. All of us. No one will be left behind."

Jim wasn't sure if Spock heard anything he said.

"Captain," Spock said after a short pause, "I would like to relieve myself of duty for the next 24 hours as I am emotionally compromised."

"Acknowledged. I will send Uhura to look for you soon."

"Captain, there is no need. She is better suited to be at the Bridge at the moment. I can—"

"Spock, the Bridge is going to be fine. Trust me."

Spock's eyes were downcast.

"Yes, Captain."

* * *

Jim was no stranger to being a Captain when he's injured or sick. Hell, he had assumed the role of Captain after going through a fight with a Vulcan and lost AND had performed in top condition.

This time though.

Being a Captain and trying to man a ship when he's emotionally tired and when two of his friends are down is something that has never happened. And this doesn't even include the absence of his best Communications Officer on the Bridge.

"Lieutenant Connor, open up the channel to Starfleet Headquarters, Admiral Fitzpatrick's Office."

"Aye, sir."

"Kirk!" Admiral Fitzpatrick sighed and ran his hand through his face, "Don't tell me, what has the _Enterprise_ done now?"

"Not us this time, Admiral."

* * *

When Jim next saw Spock, it wasn't in his room or on the observation deck, where he knew Spock liked to be when in deep meditation.

It was in the area just above the operation theatre, where they can observe everything going on in there.

He gave a short nod to Nyota, who nodded but stayed close to Spock, her hand in his.

"How is he?"

He didn't miss the brief tightening of Spock's hand around Uhura's.

 _I think you've really taught him humanity, Bones._

"Not too good," it was Nyota who answered, "I don't think he's stable yet."

Not stable was an understatement, as Jim soon found out as he pressed his face against the glass. The operation bed was a sea of red as M'Benga worked on the punctured artery. He saw the surgeons struggling to stop the bleeding as they started on the second bag of blood. He saw Bones flatlining twice, brought back only by a mixture of M'Benga's skills and the cardio-stimulator (and perhaps the Southern stubbornness inherent in Bones?). He watched as M'Benga attached the graft, cleared away the dead tissues and slowly sow his best friend back together. He watched on, past his tear filled eyes, his fists clenching and unclenching as he willed his best friend to fight for his life.

Some time in the middle of all this, he was subconsciously aware of Uhura leaving and of Spock coming to stand by his side.

He knew no words would offer comfort to the Vulcan.

 _They control their emotions… because they feel too much._

His hand rested on Spock's shoulder.

"He'll be fine."

Spock said nothing.

* * *

Star date 2270.15

The Enterprise is stationed near Vildle, waiting for Federation to send in more ships. As of now, La'thar has been stripped of all powers, and investigations against him are ongoing. Appeal for witnesses has been fruitful once we've convinced the natives to come clean with us, and more allegations against La'thar has been made. It is chilling to think that the former charming leader who once swore to stop the practice of torture and assassination of officials has reverted back to his old ways with renewed passion. Currently, talks are in process for the selection of the next leader, and possibly for the Federation's presence on the planet until things are in order again.

The Enterprise is running smoothly; most of the crew is back to their peak performance. Due to the current… situation, we are hosting Dr Sommer, who is an expert in 20th century medicine.

 _May he bring our CMO back again_

* * *

Hey Bones,

It's been almost a week since you got shot. Spock's been here everyday, almost 24 h, if it wasn't for the fact that Christine inherited some of your ninja hypo skills and knocked him out after three days, with the help of Uhura distracting Spock, of course.

Ha. I never thought I would see a Vulcan surprised, but he definitely was. Should've seen the face, Bones, it's definitely in one of our Top 10 Vulcan Expressions, somewhere near the smug look in wore on his face when he told us Carol's true identity.

So yeah, he's in the biobed next to you right now, needing an IV line because he hasn't been eating anything we've brought him. Wake up, Bones, I really need you to knock some sense into his head, because obviously it wasn't his fault, and even Starfleet has agreed.

So Bones, stay alive, please?

Hey Bones,

Its been almost ten days since you came back. You gave us quite a scare today, when your blood pressure suddenly fell, and we realised that there was something wrong with the graft. But it's alright, you're back again, and that's all that matters.

… Please don't scare us like that again alright?

Meanwhile, La'thar is getting his due desserts and will be brought back to Earth to answer to his crimes. They've found a suitable replacement, and Starfleet will assign personnel on Vildle to make sure nothing like this happens again. So yeah, dawn has finally come for the thousands of civilians living in a nightmare, fearing that they will be the next to succumb from this 'disease'.

Wake up soon, Bones. We're all waiting for you.

Hey Bones,

You must live through this, you hear me? Christine said something about sepsis-I don't know what it is, but Spock evidently did because his face became even paler, which I didn't even know was possible. He's been reading up 20th century medicine for the past few days, and when I asked him what sepsis was he listed a load of names which I haven't heard before. Dr Sommer's monitoring you around the clock right now, and I'm telling you, you can't die because I want to personally hypo you in the future for all the painful hypos you've given me.

So you better survive this, Bones.

* * *

"Spock, you've been sitting here since forever. Do you want to say something?"

"Captain, I am at a loss as to what to say."

"Oh it doesn't matter, just say something. I've been talking to Bones everyday, and I'm sure there are things you'll like to say to him as well."

Spock looked quizzically at him, and then at Nyota, who nodded encouragingly.

"Leonard?" he whispered.

The blood pressure monitor beeped in response.

Jim laughed as Spock raised his eyebrows.

* * *

Despite McCoy's constant reminder to J. T. Kirk to stop putting his own wellbeing before everyone else's and end up in the sickbay after almost every mission, what he refused to admit (and probably why he was such good friends with Jim) was that he too, was willing to do the same. As such, he wasn't alien to waking up in the sickbay and finding himself staring into the eyes of his two concerned friends.

What he was a little unused to, however, was waking up and finding himself strapped onto the bed.

"Wha-?" he attempted to voice out.

 _Have I been convulsing? Have I been hurting himself? How did I get here anyway?_

"Bones! You're awake! Spock, look he's awake! I'm going to call Nurse Chapel and Dr Sommer!"

McCoy couldn't do anything but watch as the gold uniform disappeared in a whirlwind from the room. Then, he slowly turned to the other occupant in the room, who was looking at him intently, his hand on his shoulder.

 _"_ It's alright," he whispered, his eyes closing as he suddenly felt very tired, "I'm al...right..."

"Rest well, Leonard."

"Am doctor... hobgoblin..." McCoy managed to squeeze in before he fell asleep.

* * *

 _A few weeks later…_

"Jim," sighed McCoy exasperatedly, "don't you have Captain things to do rather than come here once every hour and annoy me? I need to check up on my patients."

"Nah not really," came Jim's reply as he bit into an apple, "Spock's doing stuff, so I'm here checking on a fellow crew mate."

"Oh yeah? Which of the nurses have you got your eye on now that I should keep away from you?"

"Bones! Hmm…Starfleet doesn't approve of such fraternisation anyway."

McCoy put his pen down and glared at Kirk.

"Jim. Why. Are. You. Here."

"Alright, Bones, listen up. I've had complaints from M'Benga and Christine."

"Really? I don't see anything wrong with the MedBay."

"Not the MedBay. YOU. You've been overworking. You just recovered two weeks ago and here you are taking up your full shift and covering for a sick crew."

"Ship doesn't run by itself, Jim. Besides, some of our personnel are on Vildle setting up proper hospitals and clinics and we're a bit short of people in the MedBay at the moment, so everyone's got to pull their weight... Could you grab the bottle of blue pills on the counter?"

"Nope. You're not allowed any more pain meds."

McCoy rolled his eyes. "Like you've never done this before."

"Yeah, and whenever I do this you'll get all grouchy and threaten to hypo me into oblivion."

"Look, if you aren't getting it, I am."

"Bones…" sighed Kirk, "don't force me to show my hand…"

It was at that moment that McCoy felt a cold hand on his shoulder and knew what Kirk meant.

 _Damn Vulcan first officers_.

 _When did Spock come in anyway?_

"Alright, alright I'll take a rest," relented McCoy, climbing onto a nearby biobed, "I'm tired anyway. Always knew the Vulcan will side you."

"Doctor, Vulcans do not side anyone."

"Tell that to everyone on this ship…" came the last few words before he passed out.

Jim stared at McCoy's sleeping form, not believing that McCoy actually fell asleep in a few minutes… before his eyes caught Christine's, who was dialling for M'Benga to come down. His attention quickly turned to the cup of water that he saw Christine pass McCoy earlier when McCoy was arguing about something with Spock

 _Thou shalt not piss off the Head Nurse… and apparently, the Vulcan._

Jim crossed his arms and looked at Spock amusedly. "I suppose you know why McCoy's asleep now?"

For once, Spock did not feign innocence. "It was the most logical thing to do, Captain."

Jim snickered. "I've missed this for so long. Well done, Spock."

"Thank you, Captain."

It will end some day, some time, with one of them dying, reflected Jim as they made their way for the bridge. But until that day comes, he knew that just as the sun sets, when all hope seems lost… another dawn will rise again. And he will fight for that dawn to come until he could fight no more.

And he knew McCoy and Spock would do, too.

And that was all that mattered.

 **-The End-**

P.S. Why Vildle? I went to google "savage" in another language, and then added a few letter here and there. See if you can spot which language I used ;)  
P.P.S I'm thinking of expanding the story some day. Unfortunately, I have no idea when this 'some day' is going to be. 


End file.
